Question

5x (x+7)-x=7

Answer 1

\(\Leftrightarrow5x\left(x+7\right)-x-7=0\\ \Leftrightarrow\Leftrightarrow5x\left(x+7\right)-\left(x+7\right)=0\\ \Leftrightarrow\left(x+7\right)\left(5x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-7\\x=\dfrac{1}{5}\end{matrix}\right.\)

Answer 2

\(\Leftrightarrow5x\left(x+7\right)-\left(x+7\right)=0\\ \Leftrightarrow\left(x+7\right)\left(5x-1\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x+7=0\\5x-1=0\end{matrix}\right.\Leftrightarrow}\left[{}\begin{matrix}x=-7\\x=\dfrac{1}{5}\end{matrix}\right.\)